Impact of wind pattern and complex topography on snow microphysics during International Collaborative Experiment for PyeongChang 2018 Olympic and Paralympic winter games (ICE-POP 2018)

Snowfall in the northeastern part of South Korea is the result of complex snowfall mechanisms due to a highly contrasting terrain combined with nearby warm waters and three synoptic pressure patterns. All these factors together create unique combinations, whose disentangling can provide new insights into the microphysics of snow on the planet. This study focuses on the impact of wind flow and topography on the microphysics drawing of 20 snowfall events during the ICE-POP 2018 (International Collaborative Experiment for PyeongChang 2018 Olympic and Paralympic winter games) field campaign in the Gangwon region. The vertical structure of precipitation and size distribution characteristics are investigated with collocated MRR (micro rain radar) and PARSIVEL (particle size velocity) disdrometers installed across the mountain range. The results indicate that wind shear and embedded turbulence were the cause of the riming process dominating the mountainous region. As the strength of these processes weakens from the mountainous region to the coastal region, riming became less significant and gave way to aggregation. This study specifically analyzes the microphysical characteristics under three major synoptic patterns: air–sea interaction, cold low, and warm low. Air–sea interaction pattern is characterized by more frequent snowfall and vertically deeper precipitation systems on the windward side, resulting in significant aggregation in the coastal region, with riming featuring as a primary growth mechanism in both mountainous and coastal regions. The cold-low pattern is characterized by a higher snowfall rate and vertically deep systems in the mountainous region, with the precipitation system becoming shallower in the coastal region and strong turbulence being found in the layer below 2 km in the mountainous upstream region (linked with dominant aggregation). The warm-low pattern features the deepest system: precipitation here is enhanced by the seeder–feeder mechanism with two different precipitation systems divided by the transition zone (easterly below and westerly above). Overall, it is found that strong shear and turbulence in the transition zone is a likely reason for the dominant riming process in the mountainous region, with aggregation being important in both mountainous and coastal regions.

Impact of wind pattern and complex topography on snow microphysics during ICE-POP 2018

Snowfall in north-eastern part of South Korea is the result of complex snowfall mechanisms due to a highly-contrasting terrain combined with nearby warm waters and three synoptic pressure patterns. All these factors together create unique combinations, whose disentangling can provide new insights into the microphysics of snow in the planet. This study focuses on the impact of wind flow and topography on the microphysics drawing of twenty snowfall events during the ICE-POP 2018 (International Collaborative Experiment for Pyeongchang 2018 Olympic and Paralympic winter games) field campaign in the Gangwon region. The vertical structure of precipitation and size distribution characteristics are investigated with collocated MRR (Micro Rain Radar) and PARSIVEL (PARticle SIze VELocity) disdrometers installed across the mountain range. The results indicate that wind shear and embedded turbulence were the cause of the riming process dominating the mountainous region. As the strength of these processes weaken from the mountainous region to the coastal region, riming became less significant and gave way to aggregation. This study specifically analyzes the microphysical characteristics under three major synoptic patterns: air-sea interaction, cold low, and warm low. Air–sea interaction pattern is characterized by more frequent snowfall and vertically deeper precipitation systems in the windward side, resulting in significant aggregation in the coastal region, with riming featuring as a primary growth mechanism in both mountainous and coastal regions. The cold low pattern is characterized by a higher snowfall rate and vertically deep systems in mountainous region, with the precipitation system becoming shallower in the coastal region and strong turbulence being found in the layer below 2 km in the mountainous upstream region (linked with dominant aggregation). The warm low pattern features the deepest system: precipitation here is enhanced by the seeder–feeder mechanism with two different precipitation systems divided by the transition zone (easterly below and westerly above). Overall, it is found that strong shear and turbulence in the transition zone is a likely reason for the dominant riming process in mountainous region, with aggregation being important in both mountainous and coastal regions.

Design and Material Selection of Screw Feeder of Injection Molding Machine

The efficiency of the ‘Injection molding Machine’ lies in the proper designing of screw feeder mechanism. The screw feeding mechanism needs to be setup differently for different materials, molds etc. The proper design includes the work from selecting the appropriate materials, designing for the optimum design, analysis of the designed parts at different flow rates, speed and temperatures. There are various parameters that govern the efficiency of the ’Injection molding Machine’. These parameters include ‘Filling Pressure’, ‘Mold Surface Temperature’, ‘Raw Material Melting Temperature’, ‘Filling Time’ etc.

Automatic Fish Feeder System for Aquaponics using Wi-Fi Based WSN

Aquaponics is a farming method, which is the combination of aquaculture and hydroponics, which grows fish and plants together in one integrated system. The fish waste provides an organic food source for the plants, and the plants naturally filter the water for the fish. The purpose of this project is to build an automatic fish feeder system for aquaponics using image processing technique with the help of Wireless Sensor Network (WSN). This helps the farmers to reduce manual effort and safeguard a balanced food delivery. The number of fish in the pond may vary over time, so the amount of fish feed provided need to be changed. As there will be a large number of fish moving randomly in a pond, the manual tracking and counting of fish is very difficult. It is a time consuming and erroneous process. This work focuses on developing a system that tracks and counts the fish in the pond for aquaponics. This automatic fish identification system processes the video of the entire pond and makes it easier to estimate the count of fish. The frames from the video are processed using Raspberry-Pi board and the count of fish is transmitted through Wi-Fi. Such a system would assist to feed the fish accordingly. Based on the count transferred, a fish feeder mechanism is controlled using NodeMCU at the other end of the Wi-Fi. The amount of fish feed remaining in the feeding box is informed to the user through mobile application.

Investigation of WRF Microphysics Schemes and Dynamics During an Extreme Precipitation Event in East Idaho

Background:The 26 December 2003 snowstorm was a rare and long-lived weather system that affected east Idaho. Light snow began falling Christmas night, became steadier and heavier during the next day, and tapered off during the morning on the 27th. Snowfall estimates of 20.3-38.1 cm (8.0-15.0 in) were observed over a 24-hour period on 26 December 2003 in the lower part of the Snake River Plain, paralyzing local communities and transportation centers with snowdrifts and poor visibilities.Methods:The Weather Research and Forecasting Unified Environmental Modeling System was used to conduct a sensitivity study of five precipitation microphysics schemes at two grid scales during the event.Results:A comparison of the model accumulated total grid scale precipitation at 12-km and 4-km scales with the observed precipitation at several stations in the lower plain, indicated small negative biases (underprediction) in all of the schemes. The Purdue-Lin and Weather Research and Forecasting Double-Moment 6-Class microphysics schemes contained the smallest root mean squared errors.Conclusion:The Purdue-Lin and Weather Research and Forecasting Double-Moment 6-Class schemes provided several insights into the dynamics of the snowstorm. A topographic convergence zone, seeder-feeder mechanism, and convective instability were major factors contributing to the heavy snowfall in the lower plain.

Short-term variability and mass loss in Be stars

Context. Be stars are important reference laboratories for the investigation of viscous Keplerian discs. In some cases, the disc feeder mechanism involves a combination of non-radial pulsation (NRP) modes. Aims. We seek to understand whether high-cadence photometry can shed further light on the role of NRP modes in facilitating rotation-supported mass loss. Methods. The BRITE-Constellation of nanosatellites obtained mmag photometry of 28 Cygni for 11 months in 2014–2016. We added observations with the Solar Mass Ejection Imager (SMEI) in 2003–2010 and 118 Hα line profiles, half of which were from 2016. Results. For decades, 28 Cyg has exhibited four large-amplitude frequencies: two closely spaced frequencies of spectroscopically confirmed g modes near 1.5 c/d, one slightly lower exophotospheric (Štefl) frequency, and at 0.05 c/d the difference (Δ) frequency between the two g modes. This top-level framework is indistinguishable from η Cen (Paper I), which is also very similar in spectral type, rotation rate, and viewing angle. The circumstellar (Štefl) frequency alone does not seem to be affected by the Δ frequency. The amplitude of the Δ frequency undergoes large variations; around maximum the amount of near-circumstellar matter is increased and the amplitude of the Štefl frequency grows by a factor of a few. During such brightenings dozens of transient spikes appear in the frequency spectrum; these spikes are concentrated into three groups. Only 11 frequencies were common to all years of BRITE observations. Conclusions. Be stars seem to be controlled by several coupled clocks, most of which are not very regular on timescales of weeks to months but function for decades. The combination of g modes to the slow Δ variability and/or the atmospheric response to it appears significantly non-linear. As in η Cen, the Δ variability seems to be mainly responsible for the modulation of the star-to-disc mass transfer in 28 Cyg. A hierarchical set of Δ frequencies may reach the longest known timescales of the Be phenomenon.

Force Analysis and Experimental Study of Separator Cam of Feeder

Aimed at the stability problem of feeder, we study distribution characteristics of separator shaft torque. By a kinematic and dynamics analysis of typical feeder Mechanism, we get the force of feeder camshaft and distribution characteristics of separator torque. We study the fluctuation of separator torque using the developed feeder torque test platform. The study shows that: the theoretical analysis and experimental research of separator torque distribution is basically consistent.

Intensity-dependent parameterization of elevation effects in precipitation analysis

Elevation effects in long-term (monthly to inter-annual) precipitation data have been widely studied and are taken into account in the regionalization of point-like precipitation amounts by using methods like external drift kriging and cokriging. On the daily or hourly time scale, precipitation-elevation gradients are more variable, and difficult to parameterize. For example, application of the annual relative precipitation-elevation gradient to each 12-h sub-period reproduces the annual total, but at the cost of a large root-mean-square error. If the precipitation-elevation gradient is parameterized as a function of precipitation rate, the error can be substantially reduced. It is shown that the form of the parameterization suggested by the observations conforms to what one would expect based on the physics of the orographic precipitation process (the seeder-feeder mechanism). At low precipitation rates, orographic precipitation is "conversion-limited", thus increasing roughly linearly with precipitation rate. At higher rates, orographic precipitation becomes "condensation-limited" thus leading to an additive rather than multiplicative orographic precipitation enhancement. Also it is found that for large elevation differences it becomes increasingly important to take into account those events where the mountain station receives precipitation but the valley station remains dry.